Developer material transport

Abstract

An apparatus which develops a latent image recorded on an image receiving member with developer material. A chamber in the developer housing stores a supply of developer material. A donor roll is positioned in the chamber of the housing so as to transport developer material into contact with the latent image to develop the latent image. A rotating, elongated member fluidizes the developer material. As developer material is discharged from a storage container into the chamber of the developer housing, it exerts pressure on the fluidized developer material to move the developer material from one end of the housing to the other end thereof. An electrical bias is applied between the elongated member and the donor roll so that developer material is attracted to the donor roll as the developer material advances from one end of the developer housing to the other end thereof.

We claim: 
     
       1. An electrophotographic printing machine of the type having an electrostatic latent image recorded on a photoconductive member; wherein the improvement includes: a housing defining a chamber storing a supply of developer material therein, said housing comprises an arcuate portion;   a roller, disposed at least partially in the chamber of said housing and mounted rotatably therein, for transporting developer material into contact with the latent image recorded on the photoconductive member;   a blade having the free end region thereof resiliently urged into engagement with said roller, said blade electrically charging the developer material being advanced into contact with the latent image by said roller and metering the quantity of developer material being advanced by said roller to the latent image;   means, disposed in the chamber of said housing, for fluidizing the developer material, said fluidizing means comprises a rotatably mounted elongated member disposed interiorly of the chamber of said housing in the region of and closely adjacent to the arcuate portion of said housing, said elongated member being made from an electrically conductive material having an insulating coating thereon, said elongated member includes a cylindrical body having a plurality of saw tooth shaped paddles extending radially outwardly therefrom;   means for discharging additional developer material into the chamber of said housing with the developer material being discharged into the chamber exerting a pressure on the fluidized developer material to move the fluidized developer material from one end of said housing to the other end thereof; and   means for applying an electrical bias between said elongated member and said roller so that fluidized developer material is attracted to said roller.   
     
     
       2. An electrophotographic printing machine of the type having an electrostatic latent image recorded on a photoconductive member, wherein the improvement includes: a housing defining a chamber storing a supply of developer material therein, said housing comprises an arcuate portion;   a roller, disposed at least partially in the chamber of said housing and mounted rotatably therein, for transporting developer material into contact with the latent image recorded on the photoconductive member;   means, disposed in the chamber of said housing, for fluidizing the developer material, said fluidizing means comprises a rotatably mounted elongated member disposed interiorly of the chamber of said housing in the region of and closely adjacent to the arcuate portion of said housing, said elongated member being made from an electrically conductive material having an insulating coating thereon;   means for electrically charging the developer material being advanced into contact with the latent image by said roller, said charging means meters the quantity of developer material being advanced by said roller to the latent image, said charging means includes a blade having the free end region thereof resiliently urged into engagement with said roller;   means for discharging additional developer material into the chamber of said housing with the developer material being discharged into the chamber exerting a pressure on the fluidized developer material to move the fluidized developer material from one end of said housing to the other end thereof; and   means for applying an electrical bias between said elongated member and said roller so that fluidized developer material is attracted to said roller, said applying means includes a voltage source electrically coupled to said elongated member to apply an electrical bias between said elongated member and said roller, said voltage source applies an electrical bias arranging from about 250 volts to about 1000 volts between said elongated member and said roller.   
     
     
       3. A printing machine according to claim 2, wherein said voltage source applies an electrical bias preferably ranging from about 500 volts to about 900 volts between said elongated member and said roller. 
     
     
       4. An electrophotographic printing machine of the type having an electrostatic latent image recorded on a photoconductive member, wherein the improvement includes: a housing defining a chamber storing a supply of developer material therein, said housing comprises an arcuate portion;   a roller, disposed at least partially in the chamber of said housing and mounted rotatably therein, for transporting developer material into contact with the latent image recorded on the photoconductive member;   means for electrically charging the developer material being advanced into contact with the latent image by said roller, said charging means meters the quantity of developer material being advanced by said roller to the latent image, said charging means includes a blade having the free end region thereof resiliently urged into engagement with said roller;   means, disposed in the chamber of said housing, for fluidizing the developer material, said fluidizing means comprises a rotatably mounted elongated member disposed interiorly of the chamber of said housing in the region of and closely spaced to the arcuate portion of said housing, said elongated member being made from an electrically conductive material having an insulating coating thereon, said elongated member is spaced from said roller a distance ranging from about 0.05 centimeters to about 0.15 centimeters;   means for discharging additional developer material into the chamber of said housing with the developer material being discharged into the chamber exerting a pressure on the fluidized developer material to move the fluidized developer material from one end of said housing to the other end thereof; and   means for applying an electrical bias between said elongated member and said roller so that fluidized developer material is attracted to said roller.